NBA Playoffs: Which games mean the most?

After stealing one on the road in Houston Sunday night, as a Blazers fan I found myself thinking, “Great. No pressure in Game 2. We already got one.” Then I thought, “Wait. That’s what ESPN pundits want me to think!” I went about determining the potential gains and losses for the first two games of a first round series in the NBA Playoffs. Here’s a handy chart of the favorite’s probability of advancing to the next round, based on simulations of the playoff series with some acceptable assumptions:

Higher Seed

Neutral%

0 – 0

1 – 0

0 – 1

2 – 0

0 – 2

1 – 1

1

70.0%

89.9%

93.5%

74.9%

96.5%

48.4%

81.3%

2

64.0%

81.1%

87.8%

62.8%

93.4%

36.7%

72.1%

3

58.0%

70.5%

80.1%

50.3%

88.4%

26.4%

61.2%

4

52.0%

57.9%

69.9%

37.8%

82.1%

18.3%

49.8%

The basic assumptions include the game-by-game “neutral-court” probabilities for the favorite in the series in the chart above, as well as a 10% edge to the home team in each game. All games are considered independent of one another.

As a 5-seed, by winning its first game on the road, the Blazers increased their chances of winning the series from 42.1 percent to 62.2 percent. Had it lost, Portland would have dropped to 30.1-percent chances at winning the series. Thus, I can estimate the value of that win to be worth about 31.1 percent. Using that same methodology, the Blazers stood to gain 31.5 percent series probability by winning the second game. Essentially, for a typical 4-5 matchup in the first round, winning the second game was just as valuable as winning the first.

The value of an underdog win in Game 2 relative to a win in Game 1 increases as the matchup becomes more lopsided. An 8-seed that beats the 1-seed in the first game on the road increases it’s series chances by about 18.6 percent. Given a 0 – 1 series lead for the underdog, a Game 2 win (and thus a 0 – 2 series lead) would mean a 32.9 percent series boost relative to losing that game. Building on a series lead seems to be at least as important as creating that series lead early in the first round.

This begs the question: in the 2-2-1-1-1 first-round playoff format, in which scenario do teams stand to gain (and lose) the most series probability? Below is an chart of the crucialest to the least crucialest of series games, when the two teams are considered to be evenly matched.

Series

Home%

Diff%

3 – 3

60.0%

100.0%

2 – 3

24.0%

60.0%

2 – 2

55.2%

52.0%

1 – 2

30.7%

40.9%

3 – 2

76.0%

40.0%

1 – 1

45.9%

38.6%

2 – 1

69.3%

35.2%

1 – 0

66.2%

33.3%

0 – 0

52.8%

32.4%

0 – 1

33.8%

30.2%

2 – 0

79.2%

24.9%

0 – 2

15.7%

24.9%

1 – 3

14.3%

24.0%

3 – 1

90.4%

24.0%

0 – 3

5.8%

14.3%

3 – 0

94.2%

9.6%

To read this chart, take the 1 – 2 series as an example. When the team (originally) with home-court advantage is down 1 – 2, winning the next game would make its chances to win the series 41 percent better (55.2% – 14.3%) than losing would. This chart underscores a few things to me. The duh observation is that Game 7 has the most at stake. A more oh, you don’t say observation is that the 1 – 2 and 2 – 2 series leave a lot of probability to be tossed around in the upcoming game, despite not being elimination games.

Now that I have amused myself, I will retreat into my corner with my trusty abacus once again.

About The Author

Matthias Kullowatz

Matthias teaches statistics classes at Universities in the greater Portland area. He is well above replacement level in bodily hair volume, and slightly above replacement level in most other things. You can follow him on twitter @MattyAnselmo